save remaining syncmetadata tasks on shutdown

oml/item/models.py

@@ -873,8 +873,15 @@ def sync_metadata(ids=None):
         else:
             later = []
         if ids:
+            done = set()
             for i in Item.query.filter(Item.id.in_(ids)):
                 i.sync_metadata()
+                done.add(i.id)
+                if state.shutdown:
+                    later = list((set(later) | set(ids)) - done)
+                    if later and state.tasks:
+                        state.tasks.queue('syncmetadata', later)
+                        later = None
         if later:
             if state.main and state.tasks:
                 state.main.call_later(delay, lambda: state.tasks.queue('syncmetadata', later))